1. Field of the Invention
This invention relates to a data recording apparatus and method for recording data to be managed as a file of a predetermined format and also to a program for being executed by a data recording apparatus of the type described.
2. Description of the Related Art
A digital image pickup apparatus which can pick up moving pictures such as a digital video camera handles a moving picture file obtained by image pickup as data to be recorded on a recording medium. Therefore, a corresponding large storage capacity is demanded for the recording medium. In the past, mainly tape media were used as a storage medium which can satisfy such a demand as just mentioned. However, in recent years, also a hard disk drive (HDD) is adopted on the background of significant reduction in cost by a drop of a price per bit, enhancement of an impact resisting property and other advantages.
Since originally a HDD is used as an auxiliary storage device for a computer system, a file system of a predetermined format is adopted for management of recording data. As well known in the art, according to a file system, data stored in a storage medium are managed in a unit of a file. A FAT file system is known as one of formats for such a file system as just mentioned.
In the FAT file system, the storage area of a storage medium is divided into unit regions called clusters. Accordingly, recording of a file on the storage medium is performed such that data are successively written into a cluster or clusters. Then, the file recorded on the storage medium is managed as a concatenation of clusters in which the entity of the data is written. As well known in the art, in the FAT file system, directory entries and table information called FAT (File Allocation Table) are used as management information for managing files in such a manner as described above.
Such a FAT file system as described above is disclosed, for example, in Japanese Patent Laid-Open No. 2005-63047.
Also where a HDD is used as a storage medium of a digital video camera, it is efficient and proper to adopt a file system of a format which has been used heretofore because there is no necessity to develop a new management system. Also in an actual digital video camera with a built-in HDD, a format of a file system known already such as, for example, the FAT file system described above is adopted.
However, as described hereinabove, from such a situation that a file system such as the FAT file system has been developed under old computer systems as described above, several kinds of control to be executed by the file system are suitable for management of static files such as document files. Thus, if such control is applied as it is as control applied where stream data of a moving picture file or the like are successively recorded on the real-time basis, then unintended disadvantages may possibly occur.